An inorganic light-emitting diode (LED) display characterized by capability of emitting light and high brightness has been extensively applied in illumination devices, displays, projectors, and so on. For instance, monolithic micro-displays are extensively applied in projectors and face the technical challenge of colorization. At present, plural light-emitting layers capable of emitting different color beams can be formed in one single light-emitting diode chip through applying epitaxy techniques according to the related art, such that the one single light-emitting diode chip is able to provide different color beams. However, since the lattice constants of the light-emitting layers capable of emitting different color beams are not the same, these light-emitting layers cannot be easily formed on one substrate. Besides, another colorization technology has been proposed, wherein colorization can be achieved when different wavelength conversion materials are used to convert light emitted from the light-emitting diode chip. Specifically, when the light-emitting diode chip emits light, the wavelength conversion materials are excited to emit different color beams; however, issues of low conversion efficiency of the wavelength conversion materials and the non-uniformity of coating the wavelength conversion materials arise when such colorization technology is applied.
In addition to the aforesaid two colorization technologies, a transfer-bonding technique has also been proposed according to the related art, so as to transfer-bond the LEDs to a substrate. The LEDs capable of emitting different color beams may be respectively grown on proper substrates, such that the resultant LEDs are characterized by favorable epitaxial quality and light-emitting efficiency. Hence, the transfer-bonding technique applied to the light-emitting diode chips allows the brightness and the display quality of the monolithic micro-display to be enhanced.
At present, the transfer-bonding technique applied to the light-emitting diode chips is still notorious for low manufacturing yield and low alignment accuracy. In order to raise the manufacturing yield, the dysfunctional light-emitting diode chips that already undergo the transfer-bonding process need be replaced or repaired, which however increases manufacturing costs and labor hours. According to the related art, redundant light-emitting diode chips may be employed to replace the dysfunctional light-emitting diode chips; nevertheless, more light-emitting diode chips are required in this case, and the relevant costs will also be increased. In addition, using an excessive number of redundant light-emitting diode chips often leads to the difficulty in reducing the distance (dot pitch) among the light-emitting diode chips, which is rather unfavorable for high-resolution display.
In view of the above, how to improve the manufacturing yield without significantly increasing the costs and the arranging pitch among the light-emitting diode chips has become one of the concerns in the pertinent field.